// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2016 Imagination Technologies * Author: Paul Burton */ #include #include #include #include #include #include #include #include #include #include "line-display.h" struct img_ascii_lcd_ctx; /** * struct img_ascii_lcd_config - Configuration information about an LCD model * @num_chars: the number of characters the LCD can display * @external_regmap: true if registers are in a system controller, else false * @update: function called to update the LCD */ struct img_ascii_lcd_config { unsigned int num_chars; bool external_regmap; void (*update)(struct linedisp *linedisp); }; /** * struct img_ascii_lcd_ctx - Private data structure * @base: the base address of the LCD registers * @regmap: the regmap through which LCD registers are accessed * @offset: the offset within regmap to the start of the LCD registers * @cfg: pointer to the LCD model configuration * @linedisp: line display structure * @curr: the string currently displayed on the LCD */ struct img_ascii_lcd_ctx { union { void __iomem *base; struct regmap *regmap; }; u32 offset; const struct img_ascii_lcd_config *cfg; struct linedisp linedisp; char curr[] __aligned(8); }; /* * MIPS Boston development board */ static void boston_update(struct linedisp *linedisp) { struct img_ascii_lcd_ctx *ctx = container_of(linedisp, struct img_ascii_lcd_ctx, linedisp); ulong val; #if BITS_PER_LONG == 64 val = *((u64 *)&ctx->curr[0]); __raw_writeq(val, ctx->base); #elif BITS_PER_LONG == 32 val = *((u32 *)&ctx->curr[0]); __raw_writel(val, ctx->base); val = *((u32 *)&ctx->curr[4]); __raw_writel(val, ctx->base + 4); #else # error Not 32 or 64 bit #endif } static struct img_ascii_lcd_config boston_config = { .num_chars = 8, .update = boston_update, }; /* * MIPS Malta development board */ static void malta_update(struct linedisp *linedisp) { struct img_ascii_lcd_ctx *ctx = container_of(linedisp, struct img_ascii_lcd_ctx, linedisp); unsigned int i; int err = 0; for (i = 0; i < linedisp->num_chars; i++) { err = regmap_write(ctx->regmap, ctx->offset + (i * 8), ctx->curr[i]); if (err) break; } if (unlikely(err)) pr_err_ratelimited("Failed to update LCD display: %d\n", err); } static struct img_ascii_lcd_config malta_config = { .num_chars = 8, .external_regmap = true, .update = malta_update, }; /* * MIPS SEAD3 development board */ enum { SEAD3_REG_LCD_CTRL = 0x00, #define SEAD3_REG_LCD_CTRL_SETDRAM BIT(7) SEAD3_REG_LCD_DATA = 0x08, SEAD3_REG_CPLD_STATUS = 0x10, #define SEAD3_REG_CPLD_STATUS_BUSY BIT(0) SEAD3_REG_CPLD_DATA = 0x18, #define SEAD3_REG_CPLD_DATA_BUSY BIT(7) }; static int sead3_wait_sm_idle(struct img_ascii_lcd_ctx *ctx) { unsigned int status; int err; do { err = regmap_read(ctx->regmap, ctx->offset + SEAD3_REG_CPLD_STATUS, &status); if (err) return err; } while (status & SEAD3_REG_CPLD_STATUS_BUSY); return 0; } static int sead3_wait_lcd_idle(struct img_ascii_lcd_ctx *ctx) { unsigned int cpld_data; int err; err = sead3_wait_sm_idle(ctx); if (err) return err; do { err = regmap_read(ctx->regmap, ctx->offset + SEAD3_REG_LCD_CTRL, &cpld_data); if (err) return err; err = sead3_wait_sm_idle(ctx); if (err) return err; err = regmap_read(ctx->regmap, ctx->offset + SEAD3_REG_CPLD_DATA, &cpld_data); if (err) return err; } while (cpld_data & SEAD3_REG_CPLD_DATA_BUSY); return 0; } static void sead3_update(struct linedisp *linedisp) { struct img_ascii_lcd_ctx *ctx = container_of(linedisp, struct img_ascii_lcd_ctx, linedisp); unsigned int i; int err = 0; for (i = 0; i < linedisp->num_chars; i++) { err = sead3_wait_lcd_idle(ctx); if (err) break; err = regmap_write(ctx->regmap, ctx->offset + SEAD3_REG_LCD_CTRL, SEAD3_REG_LCD_CTRL_SETDRAM | i); if (err) break; err = sead3_wait_lcd_idle(ctx); if (err) break; err = regmap_write(ctx->regmap, ctx->offset + SEAD3_REG_LCD_DATA, ctx->curr[i]); if (err) break; } if (unlikely(err)) pr_err_ratelimited("Failed to update LCD display: %d\n", err); } static struct img_ascii_lcd_config sead3_config = { .num_chars = 16, .external_regmap = true, .update = sead3_update, }; static const struct of_device_id img_ascii_lcd_matches[] = { { .compatible = "img,boston-lcd", .data = &boston_config }, { .compatible = "mti,malta-lcd", .data = &malta_config }, { .compatible = "mti,sead3-lcd", .data = &sead3_config }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, img_ascii_lcd_matches); /** * img_ascii_lcd_probe() - probe an LCD display device * @pdev: the LCD platform device * * Probe an LCD display device, ensuring that we have the required resources in * order to access the LCD & setting up private data as well as sysfs files. * * Return: 0 on success, else -ERRNO */ static int img_ascii_lcd_probe(struct platform_device *pdev) { const struct of_device_id *match; const struct img_ascii_lcd_config *cfg; struct device *dev = &pdev->dev; struct img_ascii_lcd_ctx *ctx; int err; match = of_match_device(img_ascii_lcd_matches, dev); if (!match) return -ENODEV; cfg = match->data; ctx = devm_kzalloc(dev, sizeof(*ctx) + cfg->num_chars, GFP_KERNEL); if (!ctx) return -ENOMEM; if (cfg->external_regmap) { ctx->regmap = syscon_node_to_regmap(dev->parent->of_node); if (IS_ERR(ctx->regmap)) return PTR_ERR(ctx->regmap); if (of_property_read_u32(dev->of_node, "offset", &ctx->offset)) return -EINVAL; } else { ctx->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(ctx->base)) return PTR_ERR(ctx->base); } err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, ctx->curr, cfg->update); if (err) return err; /* for backwards compatibility */ err = compat_only_sysfs_link_entry_to_kobj(&dev->kobj, &ctx->linedisp.dev.kobj, "message", NULL); if (err) goto err_unregister; platform_set_drvdata(pdev, ctx); return 0; err_unregister: linedisp_unregister(&ctx->linedisp); return err; } /** * img_ascii_lcd_remove() - remove an LCD display device * @pdev: the LCD platform device * * Remove an LCD display device, freeing private resources & ensuring that the * driver stops using the LCD display registers. * * Return: 0 */ static int img_ascii_lcd_remove(struct platform_device *pdev) { struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev); sysfs_remove_link(&pdev->dev.kobj, "message"); linedisp_unregister(&ctx->linedisp); return 0; } static struct platform_driver img_ascii_lcd_driver = { .driver = { .name = "img-ascii-lcd", .of_match_table = img_ascii_lcd_matches, }, .probe = img_ascii_lcd_probe, .remove = img_ascii_lcd_remove, }; module_platform_driver(img_ascii_lcd_driver); MODULE_DESCRIPTION("Imagination Technologies ASCII LCD Display"); MODULE_AUTHOR("Paul Burton "); MODULE_LICENSE("GPL");